Medical operations on human or animal lumens, such as the vascular system, ureter, urethra, brain vessels, coronary vessels, lumens of the liver, kidney, lung, digestive system, and the like, can be performed by employing a medical catheter. Such medical operations include dilating a lumen by a balloon or a stent, implanting a stent, delivering a pharmaceutical substance to the lumen, performing coronary bypass, removing plaque from the intima of a blood vessel, implanting a graft, and the like. Such a medical catheter includes a lumen intervention element, such as a balloon, stent, balloon expanding stent, substance delivery element, tissue severing element, and the like, at the distal end thereof.
In some cases, the medical catheter also includes a radiopaque material at the distal end, which serves as a marker for the location of the distal end. In order to perform the medical operation, usually a guiding catheter is initially inserted in the lumen. Sometimes an auxiliary, large-diameter guidewire is inserted prior to the guiding catheter for aiding it to enable manipulation of the guiding catheter. Next, the large-diameter guidewire is pulled out, another guidewire, with of smaller diameter, is inserted in the guiding catheter and the small-diameter guidewire is advanced to the desired location within the lumen, by manipulating the tip of the small-diameter guidewire from outside the body of the patient. The proximal end of the small-diameter guidewire is inserted into the distal end of the medical catheter and the medical catheter is advanced to the desired location, by passing the medical catheter over the guidewire inside the guiding catheter. The physician determines the position of the distal end of the medical catheter, by viewing an image of the marker in an imaging device, such as fluoroscope, X-ray table, and the like. When the physician assures that the lumen intervention element is located at the desired location, the physician performs the medical task on the lumen.
U.S. Pat. No. 6,233,476 issued to Strommer et al., assigned to the present assignee, and entitled “Medical Positioning System”, is directed to a medical positioning system (MPS) for determining the position and orientation of a medical device within a living tissue. The MPS includes a 3D electromagnetic field (EMF) generator, a main sensor, an auxiliary sensor, a sensor interface, a position and orientation processor, a superimposing processor, an image interface, a 3D image database and a display unit.
The position and orientation processor is connected to the 3D EMF generator, the sensor interface and to the superimposing processor. The auxiliary sensor and the main sensor are connected to the sensor interface. The image interface is connected to the superimposing processor and to the 3D image database. The display unit is connected to the superimposing processor. The main sensor is located at the tip of the medical device. The auxiliary sensor is located in the vicinity of the inspected tissue of the patient.
The 3D image database includes a plurality of predetected images of the inspected tissue of the patient. The auxiliary sensor compensates for the movement of the patient. The 3D EMF generator includes a plurality of electromagnetic coils that produce electromagnetic fields in different directions and in different magnitudes. Each of the main sensor and the auxiliary sensor includes three electromagnetic coils. Each of the electromagnetic coils of the main sensor and the auxiliary sensor detects an electromagnetic field in a different direction. Each of the main sensor and the auxiliary sensor produces a signal in response to the electromagnetic field generated by the 3D EMF generator, corresponding to the position and orientation of the main sensor and the auxiliary sensor, respectively.
The position and orientation processor receives the signal from the main sensor through the sensor interface and the position and orientation processor determines the position and orientation of the main sensor according to this signal. The superimposing processor retrieves a predetected image of the inspected tissue from the 3D image database, through the image interface. The superimposing processor superimposes a representation of the tip of the medical device on the retrieved image and produces a video signal. The representation of the tip of the medical device corresponds to the position and orientation of the tip of the medical device relative to the inspected tissue. The display unit produces a video image according to the video signal. U.S. Pat. No. 5,646,525 issued to Gilboa and entitled “Three Dimensional Tracking System Employing a Rotating Field”, provides a description of three dimensional tracking system employed by the MPS for determining position and orientation.
U.S. Pat. No. 6,179,811 issued to Fugoso, et al., and entitled “Imbedded Marker and Flexible Guide Wire Shaft”, is directed to a balloon catheter which includes a marker band imbedded into a guidewire shaft of the balloon catheter. The balloon catheter includes a balloon, a shaft, a manifold, a guidewire shaft and a plurality of marker bands. The guidewire shaft is located within the shaft. The proximal end of the balloon is affixed to a distal end of the shaft and the distal end of the balloon is bonded to a distal end of the guidewire shaft. The manifold is located at a proximal end of the shaft. The marker bands are imbedded into the guidewire shaft at a region of the guidewire shaft below the balloon. The marker bands can be viewed by fluoroscope equipment.
U.S. Pat. No. 5,928,248 issued to Acker and entitled “Guided Deployment of Stents.”, is directed to an apparatus for applying a stent in a tubular structure of a patient. The apparatus includes a catheter, a hub, a pressure control device, a balloon, a stent, a probe field transducer, a plurality of external field transducers, a field transmitting and receiving device, a computer, an input device and a cathode ray tube. The catheter includes a bore. The hub is affixed to a proximal end of the catheter. The balloon is mounted on a distal end of the catheter. The pressure control device is connected to the balloon through the hub and the bore. The stent is made of a shape memory alloy and is located on the balloon.
The probe field transducer is located within the catheter, at a distal end thereof. The external field transducers are located outside of the patient (e.g., connected to the patient-supporting bed). The field transmitting and receiving device is connected to the external field transducers, the probe field transducer and to the computer. The computer is connected to the cathode ray tube and to the input device.
A user calibrates the field transmitting and receiving device in an external field of reference, by employing the external field transducers. The field transmitting and receiving device together with the computer, determine the position and orientation of the probe field transducer in the external field of reference. The user views the position and orientation of a representation of the stent which is located within a tubular structure of the patient, on the cathode ray tube. When the user determines that the distal end is located at the desired location within the tubular structure, the user expands the stent by operating the pressure control device and inflating the balloon, thereby positioning the stent at the desired location.
U.S. Pat. No. 5,897,529 issued to Ponzi and entitled “Steerable Deflectable Catheter Having Improved Flexibility”, is directed to a system for mapping a heart chamber and creating channels in the heart tissue. The system includes a catheter, a computer, a monitor and a pad containing coils. The catheter includes a catheter body, a control handle, an optical fiber, a puller wire, a compression coil, a tip electrode, a ring electrode, temperature sensing means, an electromagnetic sensor and a circuit board. The control handle is attached to a proximal end of the catheter body. A distal end of each of the optical fiber, the puller wire and the compression coil, is located at a distal end of the catheter body. A proximal end of each of the optical fiber, the puller wire and the compression coil, is located at a proximal end of the catheter body.
The tip electrode, the ring electrode and the temperature means are located at the distal end of the catheter body. The circuit board is located within the control handle. The circuit board is attached to the electromagnetic sensor and to the computer. The computer is connected to the monitor and to the coils. The circuit board prevents the system from being used twice, according to a signal received from the electromagnetic sensor. The compression coil provides flexibility to the catheter body.
The coils are located under the patient and generate a magnetic field. The electromagnetic sensor generates a signal in response to the generated magnetic field and the computer determines the position of the electromagnetic sensor and thus the distal end of the catheter body, by processing the signal. The tip electrode and the ring electrode monitor the strength of the electrical signals at a selected location. The temperature sensing means monitor the temperature of the tip electrode.
The tip electrode and the ring electrode allow the user to map the heart chamber. The user simultaneously maps the contours of the heart chamber, the electrical activity of the heart and the displacement of the catheter body, thereby identifying the location of an ischemic tissue. The user then creates channels in the ischemic tissue, via the optical fiber.
U.S. Pat. No. 5,830,222 issued to Makower and entitled “Device, System and Method for Interstitial Transvascular Intervention”, is directed to a method for gaining percutaneous access to a diseased vessel through an adjacent intact vessel. Using this method, it is possible to bypass the diseased vessel, such as a coronary artery, through the intact vessel, such as a cardiac vein. The diseased vessel may include an occlusion that restricts the flow. A guide-catheter is advanced through the vena cava into the coronary sinus, within the right atrium of the heart. A transvascular interstitial surgery (TVIS) guide catheter is inserted through the guide-catheter and advanced through the cardiac vein over a first guidewire, to a desired location adjacent the coronary artery.
The TVIS guide-catheter includes a balloon, a TVIS probe and either or both of active orientation detection means and passive orientation detection means. The TVIS probe is a rigid wire, antenna, light guide or energy guide capable of being inserted in tissue. The passive orientation detection means allow radiographic, fluoroscopic, magnetic or sonographic detection of position and orientation of the TVIS probe. The active orientation detection means is a transmitter. A second guidewire is inserted into the coronary artery adjacent the cardiac vein, wherein the second guidewire includes a small receiver to receive a signal emitted by the active orientation detection means. The second guidewire further includes a wire bundle which is capable to return the signal detected by the receiver, to an operator, thereby enabling the operator to determine the position and location of the TVIS probe.
When the orientation of the TVIS guide-catheter is assured, the balloon is inflated against the wall of the cardiac vein, in order to block the flow, stabilize the TVIS guide-catheter within the cardiac vein and dilate the passageway. The TVIS probe, is then advanced through the wall of the cardiac vein into the coronary artery, thereby bypassing the diseased section of the coronary artery.
U.S. Pat. No. 5,489,271 issued to Andersen and entitled “Convertible Catheter”, is directed to a percutaneous transluminal coronary angioplasty (PTCA) device, which can be used in either the rapid exchange mode or over-the-wire mode. The device includes a catheter shaft and a hub assembly. The hub assembly is bonded to a proximal end of the catheter shaft and the balloon is bonded to a distal end of the catheter shaft. The hub assembly includes a handle. The catheter shaft includes a guide element, a guidewire lumen, a balloon inflation lumen, and a third lumen in which a nitinol wire permanently resides.
In the rapid exchange mode, a first guidewire extends through the distal end of the guidewire lumen and exits from the catheter shaft, through a side port located distal of the guide element. In this mode, a stylet is located within the guidewire lumen, wherein the distal end of the stylet is proximal to the guide element and the proximal end of the stylet is bonded to the handle. In over-the-wire mode, the guide element is raised into general alignment with the wall of the catheter shaft and the stylet and the first guidewire are replaced by a second guidewire. The second guidewire extends through the guidewire lumen, from the proximal end of the device to the distal end thereof.
U.S. Pat. No. 6,035,856 issued to LaFontaine et al., and entitled “Percutaneous Bypass with Branching Vessel”, is directed to a method for performing a bypass on a first occlusion of a branching vessel of the aorta. A coronary artery which includes the first occlusion, and a branching vessel branch out of the aorta. A standard guide-catheter is advanced through the aorta up to the ostium of the branching vessel. An occlusion forming device is advanced through the guide-catheter into the branching vessel, to produce a second occlusion in the branching vessel. The occlusion device includes an elongate portion and a heated balloon.
The occlusion forming device is removed from the aorta through the guide-catheter and a cutting device is advanced through the guide-catheter proximal to the second occlusion. The cutting device includes an elongate member, a steerable guidewire, a proximal occlusion balloon, a distal balloon, a stent, a cutting blade, a first piece of magnetic material and a transmitter. The cutting blade is located distal to the distal balloon, the first piece of the magnetic material is located between the cutting blade and the distal balloon and the transmitter is located within the distal balloon. The distal balloon is located within the stent. The transmitter emits radio frequency signals.
The wall of the branching vessel is cut by employing the cutting blade. The distal balloon is kept in the expanded position, in order to occlude the branching vessel after the branching vessel has been cut. The severed end of the branching vessel is steered toward a region of the coronary artery distal to the first occlusion, by maneuvering the steerable guidewire or by manipulating the first piece of the magnetic material by a second piece of magnetic material, wherein the second piece of magnetic material is located outside the body of the patient.
The true position and the relative position of the transmitter and thus the position of the severed end of the branching vessel, is determined by employing a triangulation and coordinate mapping system. The triangulation and coordinate mapping system includes three reference electrodes which are located outside the body of the patient. Two of the reference electrodes are located on opposite sides of the heart and the third is located on the back. The three reference electrodes are used to triangulate on the transmitter.
When the severed end of the branching vessel is properly positioned, an aperture is formed in the coronary artery distal to the first occlusion, by employing the cutting blade. The severed end of the branching vessel is inserted into the coronary artery through the aperture and the stent is expanded by inflating the distal balloon, thereby attaching the severed end of the branching vessel to the lumen of the coronary artery.